Cooler module

ABSTRACT

A cooler module includes a heat sink formed of a stack of radiation fins each having a plurality of double-step mounting holes for allowing quick mounting of the radiation fins by fitting the annular outer step portions of the double-step mounting holes of one radiation fin tightly into the annular inner step portions of the double-step mounting holes of another radiation fin, a base block tightly fastened to the bottom side of the heat sink, a plurality of heat pipes tightly fitted into the double-step mounting holes of the radiation fins to reinforce engagement between the respective annular outer step portions with the corresponding annular inner step portions and tightly fitted into the bottom wall of the base block to secure the heat sink and the base block firmly together.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a cooler module for cooling an electronic chip and more particularly to such a cooler module, which has radiation fins tightly fastened together in a stack by fitting the double-step mounting holes of one radiation fin into corresponding double-step mounting holes of another radiation fin. The engagement among the double-step mounting holes is enhanced when heat pipes are inserted through the double-step mounting holes in a tight manner.

(b) Description of the Prior Art

Heat pipes are intensively used in cooler modules for cooling semiconductor chips or the like. In addition to heat pipes, a cooler module further comprises a heat sink formed of a stack of radiation fins, and a copper or aluminum base block. The radiation fins are extruded from aluminum or copper. The heat pipes are enclosed metal tubes filled with a working fluid. The base block is an aluminum or copper block.

The aforesaid heat pipes have a relatively greater diameter at one end and a relatively smaller diameter at the other end. The tolerance of the diameter is about ±0.05 mm. Therefore, the cross section of the heat pipes is not a true circle. Because of the diameter tolerance of the heat pipes, the heat pipes may not be kept in tight contact with all the radiation fins, thus lowering the structural strength or causing vibration of the radiation fins. During delivery of the cooler module, the radiation fins may be damaged easily. Solder bonding may be employed to reinforce the structural strength. However, this extra processing causes environmental pollution, and greatly complicates the fabrication of the cooler module and increases its cost.

FIG. 8 shows a prior art design, in which each heat pipe mounting hole of each radiation fin 10 has step portion 101. By means of stopping the step portions 101 of the heat pipe mounting holes of one radiation fin 10 against the corresponding step portions 101 of the heat pipe mounting holes of another radiation fin 10, the radiation fins 10 are arranged in a stack. Thereafter, heat pipes 20 are fitted into the heat pipe mounting holes of the radiation fins 10 to enhance the engagement of the step portions 101 of the radiation fins 10. However, because the heat pipes 20 do not have a true roundness, and the diameter of the heat pipes 20 has a tolerance about ±0.05 mm, the heat pipes 20 may not be kept in close contact with the radiation fins 10. Therefore, the radiation fins 10 may be loosened easily, thus lowering the heat dissipation performance of the cooler module.

SUMMARY OF THE INVENTION

The present invention has been accomplished under the circumstances in view. According to one aspect of the present invention, the cooler module comprises a plurality of radiation fins, a plurality of heat pipes, a base block, and a thermal pad. The radiation fins each have a plurality of double-step mounting holes, which receive the heat pipes tightly. The double-step mounting holes each have an annular inner step portion and an annular outer step portion. The annular outer step portion of one double-step mounting hole of one radiation fin is tightly fitted into the annular inner step portion of the corresponding double-step mounting hole of another radiation fin so that the radiation fins are tightly fastened together in a stack. The heat pipes are respectively tightly fitted into the double-step mounting holes of the radiation fins to force the annular outer step portions of the double-step mounting holes of the radiation fins against the corresponding annular inner step portions of the double-step mounting holes of the neighboring radiation fins, reinforcing the structural strength and enhancing the heat dissipation effect.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of a cooler module in accordance with the present invention.

FIG. 2 is an elevational assembled view of the cooler module in accordance with the present invention.

FIG. 3 is a side view of the cooler module in accordance with the present invention.

FIG. 4 is a sectional view of the cooler module in accordance with the present invention, taken along line 4-4 of FIG. 3.

FIG. 5 is an enlarged view of a part of FIG. 4.

FIG. 6 is a schematic drawing showing the fitting of one heat pipe into one double-step mounting hole of each of the radiation fins according to the present invention.

FIG. 7 is an exploded view of a U-turn cooler module.

FIG. 8 is a schematic sectional assembled view of radiation fins and one heat pipe according to the prior art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, a cooler module in accordance with a first embodiment of the present invention is shown comprised of a heat sink 1, which is formed of a stack of first radiation fins 11 a and second radiation fins 11 b, a plurality of heat pipes 2, and a base block 3 (see also FIGS. 2 and 3).

The heat pipes 2 are enclosed metal pipes filled with a working fluid, each having a selected part (an extension (see FIGS. 1 and 2) arm or U-turn (see FIG. 7)) bonded to the base block 3. The base block 3 is a solid metal (copper or aluminum) block tightly fastened with the heat pipes 2. The bottom surface of the base block 3 may be mounted with a thermal pad 4 (by means of rivet or tongue-and-groove joint, or compression bonding technique).

The main feature of the present invention is at the mounting arrangement between the heat sink 1 and the heat pipes 2. The radiation fins 11 a or 11 b each have a plurality of double-step mounting holes 13 for receiving the heat pipes 2 tightly (see FIGS. 2 through 4). Each double-step mounting hole 13 has an outer step portion 131 and an inner step portion 132 (see FIG. 5), i.e., each double-step mounting hole 13 has two annular steps of different diameters such that the radiation fins 11 a and 11 b can be firmly arranged in a stack by tightly fitting the outer step portion 131 of each of the double-step mounting holes 13 of one radiation fin 11 a or 11 b into the inner step portion 132 of one of the double-step mounting holes 13 of another radiation fin 11 a or 11 b. When the radiation fins 11 a and 11 b are fastened together, the associated double-step mounting holes 13 form respective through holes into which the heat pipes 2 are tightly fitted.

Referring to FIG. 6, the inner diameter C of the inner step portions 132 of the double-step mounting holes 13 of the radiation fins 11 a and 11 b is slightly smaller than the outer diameter A of the outer step portions 131 of the double-step mounting holes 13 of the radiation fins 11 a and 11 b.

Therefore, the double-step mounting holes 13 of one radiation fin 11 a or 11 b can be tightly fitted into the double-step mounting holes 13 of another radiation fin 11 a or 11 b. Further, the inner diameter B of the outer step portions 131 of the double-step mounting holes 13 of the radiation fins 11 a and 11 b is slightly smaller than the outer diameter D of the heat pipes 2 so that the heat pipes 2 can be tightly fitted into the double-step mounting holes 13 of the radiation fins 11 a and 11 b to enhance engagement between the respective outer step portions 131 and the respective inner step portions 132. Therefore, the radiation fins 11 a and 11 b and the heat pipes 2 are firmly secured together to provide a high strength against impact during delivery or installation. Further, because the radiation fins 11 a and 11 b are kept in close contact with the heat pipes 2, the cooler module provides excellent heat transfer and dissipation effects.

Further, the radiation fins 11 a and 11 b have the respective bottom edge configured to fit the configuration of the top wall of the base block 3. The heat pipes 2 each have a flat bottom wall disposed in flush with the bottom wall of the base block 3. Further, the thermal pad 4 is bonded to the bottom wall of the base block 3 to wrap the heat pipes 2 tightly (see FIG. 3). After installation, the thermal pad 4 has its top and bottom surfaces respectively disposed in contact with the flat bottom walls of the heat pipes 2 and the hot side of the electronic chip (such as CPU or GPU). When the thermal pad 4 and the heat pipes 2 are hot during dissipation of heat from the electronic chip, the heat expansion effect reinforces the surface contact between the heat pipes 2 and the thermal pad 4. Therefore, heat can be transferred from the electronic chip to the heat pipes 2 rapidly for quick dissipation.

A prototype of cooler module has been constructed with the features of FIGS. 16. The cooler module functions smoothly to provide all of the features discussed earlier.

Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims. 

1. A cooler module, comprising a heat sink formed of a stack of radiation fins, a base block attached to said heat sink, and a plurality of heat pipes tightly inserted through the radiation fins of said heat sink and closely attached to said base block, wherein: said radiation fins each have a plurality of double-step mounting holes, which receive said heat pipes tightly, said double-step mounting holes each having an annular inner step portion and an annular outer step portion, the annular outer step portion of each of the double-step mounting holes of said radiation fins being respectively and tightly fitted into the annular inner step portion of a corresponding double-step mounting hole of respective neighboring radiation fins; and said heat pipes are respectively tightly fitted into the double-step mounting holes of said radiation fins to force the annular outer step portions of the double-step mounting holes of said radiation fins against the annular inner step portions of the corresponding double-step mounting holes of said neighboring radiation fins.
 2. The cooler module as claimed in claim 1, wherein the annular inner step portions of said double-step mounting holes have an inner diameter smaller than the outer diameter of the annular outer step portions of said double-step mounting holes.
 3. The cooler module as claimed in claim 1, wherein the annular outer step portions of said double-step mounting holes have an inner diameter smaller than the outer diameter of said heat pipes.
 4. The cooler module as claimed in claim 1, wherein said heat sink has a bottom side configured to fit a top wall of said base block.
 5. The cooler module as claimed in claim 1, further comprising a thermal pad bonded to a bottom wall of said base block to cover said heat pipes and to hold down said heat pipes in the bottom wall of said base block.
 6. The cooler module as claimed in claim 1, wherein said heat pipes each have an extension arm tightly fitted into said base block.
 7. The cooler module as claimed in claim 1, wherein said heat pipes each have a U-turn tightly fitted into said base block. 